Investigating the applicability of the finite integration technique for studying the frequency response of the transformer winding

The frequency response analysis (FRA) is a promising diagnostic method for detecting mechanical faults inside a power transformer. Despite the standardization of the FRA measurement procedure, the interpretation of the results is still a subject of study. The reason lies in the fact that the frequency response is different from case to case, Therefore, for interpreting a transformer FRA result, the effects of various possible mechanical changes on the FRA trace of that particular transformer should be known. Additionally, real mechanical deformations cannot be executed for obtaining the required information due to the destructive nature. Hence, the transformer winding models are utilized instead to study the frequency response. While the circuit model has been extensively discussed in the literature, there is little focus on the numerical methods for the FRA purpose. To take a step forward, this contribution investigates the applicability of the finite integration technique for the FRA studies. The presented model can simulate different fault types for the FRA interpretation while it has also other applications regarding the frequency response. In this contribution, the FRA traces are derived directly from a finite integration model which is an important improvement compared with the previous papers. The agreement between the simulation results and the experimental data indicates that the proposed model has the potential of providing a powerful tool to decipher the transformer frequency behavior.